The brain is a magical apparatus, but easily fooled. Take these low-tech 3D images from Burning Man. By shooting stereoimages (i.e. two images taken simultaneously through lenses next to each other at a distance similar to eye distance) and displaying them, shifting rapidly between left and right image you get a much better experience of depth than you would expect from such a simple minded approach. I would love to see this applied to film. You could do that intelligently, using simultaneous panning and left/right shifts to get the 3D effect without quite so much of a wiggling sensation.